Research on microbial ecosystems is often challenging due to the high diversity of microbial taxa present and the complexity of controlling environmental variables. Fermented foods offer simpler and more reproducible model ecosystems in which both community composition and environmental factors can be more precisely controlled and manipulated. In this study, we focused on fermented vegetables, which are typically dominated by lactic acid bacteria (LAB). However, it remains unclear why LAB consistently drive the spontaneous fermentation of vegetables and how factors such as vegetable substrates, salt addition, and carbon dioxide levels shape microbial community dynamics. We characterized the temporal microbial succession in standardized spontaneous fermentations of 11 different vegetables (including beetroot, bell pepper, cabbage, carrot, cucumber, fennel, green asparagus, leek, parsnip, sunroot, and tomato), revealing a robust and recurrent dominance of Leuconostoc and other LAB across substrates. Additionally, we investigated the impact of varying salt concentrations and found that lower salt levels delayed the establishment of the typically LAB-dominated community, while promoting a higher abundance of Weissella and multiple Enterobacterales taxa. Notably, these salt reduction-induced effects were mitigated by CO2 injection, which reduced Enterobacterales levels and increased the overall abundance of Lactobacillales. Together, these findings demonstrate how targeted manipulation of environmental parameters, such as salinity and gas composition, can be used to uncover ecological principles governing microbial succession and community assembly in reproducible fermentation-based model ecosystems. IMPORTANCE:Understanding the ecological principles that shape microbial community assembly is essential for advancing our knowledge of microbial ecosystems. Fermented vegetables, which are increasingly popular among the general population, provide a tractable and reproducible model system to study microbial succession. By systematically manipulating variables such as vegetable substrate, salinity, and gas composition, we identified the effects of these factors on microbial dynamics throughout the fermentation. These insights not only enhance our understanding of the microbial ecology of these man-made food systems but also suggest directions for novel strategies to optimize fermentation processes for the production of faster, safer, and more flavorful foods.

IntroductionBioremediation is an emerging, sustainable strategy that relies on microbial processes to detoxify environmental pollutants. Among these pollutants, heavy metals (HMs) are pervasive, non-degradable toxic elements that pose serious risks to human health. In this study, we individually evaluated three probiotic lactobacilli strains—Lactiplantibacillus plantarum LP14, Lactobacillus crispatus LCR04, and Lactobacillus acidophilus LA12—for their capacity to detoxify cadmium, chromium, mercury, and lead in the gastrointestinal (GI) tract, as well as their capacity to mitigate heavy metal-induced intestinal damage, with a single-strain product strategy in mind.MethodsAfter initial selection of the strains for their in vitro detoxifying potential, we employed a dynamic Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) model and each strain’s survival, growth, and heavy metal detoxification capacity was assessed under sequential gastric, small-intestinal, and colonic conditions.ResultsStrain- and metal-specific differences in HMs sequestration emerged: L. plantarum LP14 and L. crispatus LCR04 showed robust persistence and significantly reduced HMs bioavailability, whereas L. acidophilus LA12 displayed minimal detoxification under GI simulation. Mechanistically, only the strains that proliferated in the colonic phase achieved substantial HM removal, underscoring the importance of metabolic activity in situ. In a gut ex vivo system (GEVS), heavy metal exposure alone compromised epithelial barrier integrity and triggered pro-inflammatory responses. Pre-incubation of the HMs with each of the probiotic strains markedly alleviated these effects, restoring intestinal permeability and cytokine profiles.DiscussionOverall, the results demonstrate a novel probiotic-based intestinal bioremediation strategy and highlight the translational potential of targeted single-strain probiotic interventions, reducing heavy metal exposure to protect gut health.

Lactobacillus crispatus is a dominant member of the healthy vaginal microbiota, yet the mechanisms by which it modulates host immunity remain poorly defined, in part due to the lack of tractable in vivo models. Here, we integrate bacterial genetics, in vitro epithelial systems, human-derived data and proteomic approach (Olink®) to uncover a critical role for L. crispatus exopolysaccharides (EPS) in shaping the bacteria-vagina interactions. Comparative genomics identified a conserved EPS biosynthetic locus, with the priming glycosyltransferase gene epsE emerging as a regulatory node, in line with its distinct expression in human vaginal samples. Functional disruption of epsE abrogated L. crispatus EPS production and revealed its role for immune modulation. In human vaginal epithelial monolayers, EPS presence enhanced immune-regulatory (LAP TGF-beta-1) and anti-inflammatory (CST5) responses, whereas its absence triggered elevated pro-inflammatory cytokines (IL1β, IL6, IL8) and matrix metalloproteinase (MMP10). In a 3D vaginal organotypic model, EPS increased chemokines (CXCL5, CXCL6) linked to immune surveillance and the presence of the markers was validated in vaginal samples of healthy volunteers. These findings position EPS as a key immunomodulatory structure of L. crispatus, advancing our mechanistic understanding of host-commensal interactions and informing microbiome-based strategies to promote vaginal health.

Modern diets typically contain dramatically lower fiber content compared to traditional hunter-gatherer and agrarian diets, and this trend is paralleled by an enhanced frequency of chronic diseases. Despite national nutrition policy and education instructing Americans on the beneficial health value of increasing daily fiber consumption, a “fiber gap” still persistently exists. Fortification of product groups frequently consumed by a large proportion of society provides an attractive strategy to close this “fiber gap” and may have the potential to concomitantly reverse the detrimental health effects exacerbated by our modern diets. Besides prebiotic fibers, products can contain several other functional components, such as botanicals. However, the vast majority of studies have investigated functional components in isolation. For instance, preferential fermentation of specific prebiotic fibers by bifidobacteria has been clearly established, both in terms of their increased abundance in the gut microbiome and the elevated levels of beneficial metabolites, including short chain fatty acids (SCFAs) produced directly (acetate) or through interactions with other microbiota members (resulting in butyrate and propionate production). The impact of other components present in functional product blends on this bifidogenic effect are largely unexplored. Here, we investigated the fiber and botanical blends included in OLIPOP, a functional soda, in an in vitro gut fermentation model. Our data revealed that the blend of inulins and resistant dextrins promoted growth of bifidobacteria across gut microbiota from four donors, even those with small initial populations. In addition, botanicals interacted with fiber fermentation in donor-specific ways, in some cases strongly enhancing fermentation rate and production of SCFAs. Our data suggest that botanicals can modify the rate and microbial and metabolic fates of prebiotic fiber fermentation, and suggest that future studies should examine such interactions in greater detail.

The increasing numbers of sexual violence and unresolved rape cases require alternative approaches with higher evidential value to complement existing forensic tools. Predicting recent intercourse is crucial in forensic casework on sexual assaults. In this work, we assessed whether sexual intercourse can be predicted based on the vaginal microbiome and compared it to the gold standard method of semen detection. Using a prediction model based on microbiome of 3043 women, intercourse was predicted with 71

Predicting recent intercourse is crucial in forensic casework on sexual assaults. In this work, we assessed whether sexual intercourse can be predicted based on the vaginal microbiome and compared it to the gold standard method of semen detection. Using a prediction model based on microbiome of 3,043 women, intercourse was predicted with 71% accuracy in a balanced cross-validation machine learning setting. Next, this prediction model was validated in a longitudinal intervention study and tested on forensic sexual assault cases. The developed predictor could accurately establish intercourse in 82% cases. Yet, underwear was found to hold an even greater evidential value and replace the more invasive vaginal sampling for semen detection in some cases, with an accuracy of 95%. This was confirmed through a retrospective analysis of 207 forensic sexual assault cases. Taken together, this study revealed the potential of both microbiome profiling on vaginal swabs and semen detection on underwear for forensic casework.

Carotenoids are membrane-bound pigments that are essential for photosynthesizing plants and algae, widely applied in food, feed and cosmetics due to their antioxidant and anti-inflammatory properties. The production of carotenoids, particularly C30 forms, has been documented in some non-photosynthetic prokaryotes. However, their function, distribution and ecology beyond photosynthesizing organisms remains understudied. In this study, we performed an eco-evolutionary analysis of terpenoid biosynthetic gene clusters in the Lactobacillaceae family, screening 4203 dereplicated genomes for terpenoid biosynthesis genes, and detected crtMN genes in 28/361 (7.7%) species across 14/34 (41.2%) genera. These genes encode key enzymes for producing the C30 carotenoid 4,4 '-diaponeurosporene. crtMN genes appeared to be convergently gained within Fructilactobacillus and horizontally transferred across species and genera, including Lactiplantibacillus to Levilactobacillus. The phenotype was confirmed in 87% of the predicted crtMN gene carriers (27/31). Nomadic and insect-adapted species, particularly those isolated from vegetable fermentations, e.g., Lactiplantibacillus, and floral habitats, e.g., Fructilactobacillus, contained crtMN genes, while vertebrate-associated species, including vaginal associated species, lacked this trait. This habitat association aligned with the observations that C30 carotenoid-producing strains were more resistant to UV-stress. In summary, C30 carotenoid biosynthesis plays a role in habitat adaptation and is scattered across Lactobacillaceae in line with this habitat adaptation.

Dairy industries apply selected lactococcal strains and mixed cultures to produce diverse fermented products with distinctive flavor and texture properties. Innovation of the starter culture functionality in cheese applications embraces natural biodiversity of the Lactococcus species to identify novel strains with alternative flavor or texture forming capacities and/or increased processing robustness and phage resistance. Mobile genetic elements (MGE), like integrative conjugative elements (ICEs) play an important role in shaping the biodiversity of bacteria. Besides the genes involved in the conjugation of ICEs from donor to recipient strains, these elements also harbor cargo genes that encode a wide range of functions. The definition of such cargo genes can only be achieved by accurate identification of the ICE boundaries (delimiting). Here, we delimited 25 ICEs in lactococcal genome sequences with low contig numbers using insertion-sites flanking single-copy core-genome genes as markers for each of the distinct ICE-integrases we identified previously within the conserved ICE-core genes. For ICEs in strains for which genome information with large numbers of contigs is available, we exemplify that CRISPR-Cas9 driven ICE-curing, followed by resequencing, allows accurate delimitation and cargo definition of ICEs. Finally, we compare and contrast the cargo gene repertoire of the 26 delimited lactococcal ICEs, identifying high plasticity among the cargo of lactococccal ICEs and a range of encoded functions that is of apparent industrial interest, including restriction modification, abortive infection, and stress adaptation genes.

Lactococcus lactis is widely applied by the dairy industry for the fermentation of milk into products such as cheese. Adaptation of L. lactis to the dairy environment often depends on functions encoded by mobile genetic elements (MGEs) such as plasmids. Other L. lactis MGEs that contribute to industrially relevant traits like antimicrobial production and carbohydrate utilization capacities belong to the integrative conjugative elements (ICE). Here we investigate the prevalence of ICEs in L. lactis using an automated search engine that detects colocalized, ICE-associated core-functions (involved in conjugation or mobilization) in lactococcal genomes. This approach enabled the detection of 36 candidate-ICEs in 69 L. lactis genomes. By phylogenetic analysis of conserved protein functions encoded in all lactococcal ICEs, these 36 ICEs could be classified in three main ICE-families that encompass 7 distinguishable ICE-integrases and are characterized by apparent modular-exchangeability and plasticity. Finally, we demonstrate that phylogenetic analysis of the conjugation-associated VirB4 ATPase function differentiates ICE- and plasmid-derived conjugation systems, indicating that conjugal transfer of lactococcal ICEs and plasmids involves genetically distinct machineries. Our genomic analysis and sequence-based classification of lactococcal ICEs creates a comprehensive overview of the conserved functional repertoires encoded by this family of MGEs in L. lactis, which can facilitate the future exploitation of the functional traits they encode by ICE mobilization to appropriate starter culture strains.

Atopic dermatitis is the most common inflammatory skin condition with a severe negative impact on patients’ quality of life. The etiology of AD is complex and depends on age, genetics, the immune system, environmental factors, and the skin microbiome, with a key role for pathogenic Staphylococcus aureus in the development of severe AD. However, the composition of the skin microbiome in mild AD is understudied. Here, using metagenomic shallow shotgun sequencing, we showed that mild AD lesions did not show a significant difference in the diversity of the skin microbiome compared to samples from non-AD patients and that the relative abundance of S. aureus did not differ in these mild AD lesions. However, when we assessed other taxa, Mycobacterium ostraviense, Pedobacter panaciterrae_A and four Streptomyces species were identified with higher abundances in mild AD lesions and species of 15 genera were decreased in abundance. The highest fold decreases were observed for Paracoccus marcusii, Microbacterium lacticum, Micrococcus luteus, and Moraxella sp002478835. These microbiome compositional insights are a first step towards novel microbiome-based diagnostics and therapeutics for early intervention at the stage of mild AD and provide a path forward for the functional study of species involved in this often-overlooked patient population.

Background: The human skin microbiome plays an essential role in protecting against pathogens and other external substances. This open ecosystem is also influenced by personal and environmental factors, but the precise impact of these factors, such as lifestyle and season, is understudied. We focused here on the inner elbow, a skin site prone to inflammatory conditions like atopic dermatitis and psoriasis. Methods: We collected skin swabs from the inner elbow of 52 children and adults, with no signs of skin disorders, in the winter and summer seasons. Samples were analyzed using metagenomic shallow shotgun sequencing. In addition, metadata were collected using questionnaires on health, lifestyle, and environmental factors. Results: The core inner elbow community, taxa with a prevalence of 95% or higher, consisted of several well-known skin taxa, such as Staphylococcus hominis , Staphylococcus capitis , Staphylococcus epidermidis , and Cutibacterium acnes . In addition, Streptococcus and Lactobacillus species were also found to be highly prevalent members of the skin microbiota, especially in the age group up to 3 years old. Of all investigated factors, age appeared to be the major driver defining the skin microbiome composition and longitudinal stability over the seasons. Differential abundance analysis using three statistical tests also pointed out that specific skin species were significantly associated with sampling season, age, hygiene practices, vitamin D supplements, probiotics, and the number of household members. Conclusion: This study identifies novel factors influencing the inner elbow skin microbiome composition and paves the way for future comparative and intervention studies in skin disorders such as atopic dermatitis.

Respiratory viruses such as influenza viruses, respiratory syncytial virus (RSV), and coronaviruses initiate infection at the mucosal surfaces of the upper respiratory tract (URT), where the resident respiratory microbiome has an important gatekeeper function. In contrast to gut-targeting administration of beneficial bacteria against respiratory viral disease, topical URT administration of probiotics is currently underexplored, especially for the prevention and/or treatment of viral infections. Here, we report the formulation of a throat spray with live lactobacilli exhibiting several in vitro mechanisms of action against respiratory viral infections, including induction of interferon regulatory pathways and direct inhibition of respiratory viruses. Rational selection of Lactobacillaceae strains was based on previously documented beneficial properties, up-scaling and industrial production characteristics, clinical safety parameters, and potential antiviral and immunostimulatory efficacy in the URT demonstrated in this study. Using a three-step selection strategy, three strains were selected and further tested in vitro antiviral assays and in formulations: Lacticaseibacillus casei AMBR2 as a promising endogenous candidate URT probiotic with previously reported barrier-enhancing and anti-pathogenic properties and the two well-studied model strains Lacticaseibacillus rhamnosus GG and Lactiplantibacillus plantarum WCFS1 that display immunomodulatory capacities. The three strains and their combination significantly reduced the cytopathogenic effects of RSV, influenza A/H1N1 and B viruses, and HCoV-229E coronavirus in co-culture models with bacteria, virus, and host cells. Subsequently, these strains were formulated in a throat spray and human monocytes were employed to confirm the formulation process did not reduce the interferon regulatory pathway-inducing capacity. Administration of the throat spray in healthy volunteers revealed that the lactobacilli were capable of temporary colonization of the throat in a metabolically active form. Thus, the developed spray with live lactobacilli will be further explored in the clinic as a potential broad-acting live biotherapeutic strategy against respiratory viral diseases.

The human gut microbiome contributes crucial bioactive metabolites that support human health and is sensitive to perturbations from the ingestion of alcohol and antibiotics. We interrogated the response and recovery of human gut microbes after acute alcohol or broad-spectrum antibiotic administration in a gut model simulating the luminal and mucosal colonic environment with an inoculated human microbiome. Both alcohol and antibiotic treatments reduced the production of major short-chain fatty acids (SCFAs) (acetate, propionate, and butyrate), which are established modulators of human health. Treatment with a microbial synbiotic restored and enhanced gut function. Butyrate and acetate production increased by up to 29.7% and 18.6%, respectively, relative to untreated, dysbiotic samples. In parallel, treatment led to increases in the relative abundances of beneficial commensal organisms not found in the synbiotic (e.g., Faecalibacterium prausnitzii and the urolithin-producing organism Gordonibacter pamelaeae) as well as species present in the synbiotic (e.g., Bifidobacterium infantis), suggesting synergistic interactions between supplemented and native microorganisms. These results lead us to conclude that functional shifts in the microbiome, evaluated by both metabolite production and specific taxonomic compositional changes, are an appropriate metric to assess microbiome "recovery" following a dysbiosis-inducing disruption. Overall, these findings support the execution of randomized clinical studies to determine whether a microbial synbiotic can help restore microbiome function after a disruption. IMPORTANCE The human gut microbiome is sensitive to disruptions by common stressors such as alcohol consumption and antibiotic treatment. In this study, we used an in vitro system modeling the gut microbiome to investigate whether treatment with a microbial synbiotic can help restore microbiome function after stress. We find that a complex gut community treated with alcohol or antibiotics showed reduced levels of production of short-chain fatty acids, which are critical beneficial molecules produced by a healthy gut microbiota. Treatment of stressed communities with a microbial synbiotic resulted in the recovery of SCFA production as well as an increase in the abundance of beneficial commensal organisms. Our results suggest that treatment with a microbial synbiotic has the potential to restore healthy gut microbiome function after stress and merits further investigation in clinical studies.

ABSTRACT The human salivary microbial community plays a crucial role in local and systemic diseases. Biological and lifestyle factors such as menstrual cycle, oral hygiene, and smoking have been documented to impact this community. However, while hormonal contraceptives are the most prescribed drug in healthy women and intimate partners play key roles in microbial exchange between humans, their impact on the salivary microbiome of women of reproductive age have been understudied. Additionally, the role of other lifestyle factors such as diet, allergies, age, and stress on the saliva microbiome of the general population is not well understood. Here, we studied the salivary microbiome of 255 healthy women of reproductive age using self-sampling kits and 16S rRNA amplicon sequencing combined with questionnaires on lifestyle and host-related parameters. A preserved salivary bacterial community of 12 genera (Actinobacillus, Actinomyces, Alloprevotella, Campylobacter, Fusobacterium, Gemella, Granulicatella, Leptotrichia, Neisseria, Prevotella, Streptococcus, and Veillonella) was identified. Contrary to what we expected, the number of intimate partners or specific contraceptive use did not have a major impact on these bacterial communities. However, recent use of oral antibiotics was associated with a significant decrease in richness at genus level and increase in mean relative abundances of several taxa. Being stressed or nervous was associated with a significantly increased richness of the salivary microbiome at the level of amplicon sequencing variants . Nevertheless, these associations with host-related and lifestyle variables only appeared to be subtle, suggesting that the salivary microbiome is mainly driven by the buccal environment and health status of an individual. IMPORTANCE The salivary microbiome has been proven to play a crucial role in local and systemic diseases. Moreover, the effects of biological and lifestyle factors such as oral hygiene and smoking on this microbial community have already been explored. However, what was not yet well understood was the natural variation of the saliva microbiome in healthy women and how this is associated with specific use of hormonal contraception and with the number of different sexual partners with whom microbiome exchange is expected regularly. In this paper, we characterized the salivary microbiome of 255 healthy women of reproductive age using an in-depth questionnaire and self-sampling kits. Using the large metadata set, we were able to investigate the associations of several host-related and lifestyle variables with the salivary microbiome profiles. Our study shows a high preservation between individuals.

Understanding the composition and function of the vaginal microbiome is crucial for reproductive and overall health. Here we established the Isala citizen-science project to analyse the vaginal microbiomes of 3,345 women in Belgium (18-98 years) through self-sampling, 16S amplicon sequencing and extensive questionnaires. The overall vaginal microbiome composition was strongly tied to age, childbirth and menstrual cycle phase. Lactobacillus species dominated 78% of the vaginal samples. Specific bacterial taxa also showed to co-occur in modules based on network correlation analysis. Notably, the module containing Lactobacillus crispatus, Lactobacillus jensenii and Limosilactobacillus taxa was positively linked to oestrogen levels and contraceptive use and negatively linked to childbirth and breastfeeding. Other modules, named after abundant taxa (Gardnerella, Prevotella and Bacteroides), correlated with multiple partners, menopause, menstrual hygiene and contraceptive use. With this resource-rich vaginal microbiome map and associated health, life-course, lifestyle and dietary factors, we provide unique data and insights for follow-up clinical and mechanistic research.

OPINION article Front. Endocrinol., 11 March 2022Sec.Gut Endocrinology https://doi.org/10.3389/fendo.2022.804179

The number of live bacterial cells is the most used parameter to assess the quality of finished probiotic products. Plate counting (PC) is the standard method in industry to enumerate cells. Application of PC implies critical aspects related to the selection of optimal nutrient media and growth conditions and underestimation of viable but not cultivable (VBNC) cells. Flow-cytometry (FC) is a culture-independent methodology having the potential to selectively enumerate live, damaged, and dead cells representing a powerful tool for in-depth monitoring of probiotic products. We monitored the shelf life of a clinical batch of a synbiotic composition PDS-08 targeting the pediatric population by means of PC and FC according to International Conference on Harmonization (ICH) pharma guidelines testing the Arrhenius model as predictive tool; PC enumeration revealed higher destruction rate than FC suggesting a faster reduction in cultivability than membrane integrity and thus a possible shift of the bacteria into a VBNC status. PDS-08 maintained acidification capability over time, when re-suspended in nutrient medium, even in samples tested sub-optimally for CFU detection (below 1 billion cells/dose). Due to similar kinetics described by the study of metabolic activity and membrane integrity, FC might be suggested as a valid tool for the study of functional stability of a probiotic product.

The vaginal microbiome is crucial for women’s health and reproduction, but its ecology and determinants in the general population are still unclear. This lack of a reference framework hampers much-needed innovations in diagnostics and therapeutics. Here, we remotely mapped the vaginal microbiome of 3,345 women in Western Europe via a citizen-science approach. More than 75% of the vaginal samples were dominated by Lactobacillus taxa, but not in discrete community state types. Compositional correlation network analysis validated with public data pointed at six main modules of interacting microbes: a Lactobacillus crispatus-, Lactobacillus iners-, Gardnerella-, Prevotella-, Anaerococcus- , and gut-derived module. In the first module, Limosilactobacillus taxa were functionally connected to L. crispatus and Lactobacillus jensenii . This module was positively associated with the luteal phase of the menstrual cycle and negatively with the number of vaginal complaints, while the Gardnerella -module was associated with discharge and increasing age. Contraceptives with oestrogen correlated with higher levels of the L. crispatus - and less of the Gardnerella -module, with the opposite found for a hormonal intrauterine device or having multiple partners. Mothers had lower relative abundance of the L. crispatus -module and more Bifidobacterium, Lactobacillus gasseri and Streptococcus . Other covariates such as BMI, menstrual pads and cups, smoking and dietary habits were also associated with the microbial constellation. These findings suggest that lifestyle interventions have potential to improve vaginal health when combined with dedicated therapies.

Riboflavin-producing lactic acid bacteria represent a promising and cost-effective strategy for food biofortification, but production levels are typically insufficient to support daily human requirements. In this study, we describe the novel human isolate Limosilactobacillus reuteri AMBV339 as a strong food biofortification candidate. This strain shows a high natural riboflavin (vitamin B2) overproduction of 18.36 μg/ml, biomass production up to 6 × 1010 colony-forming units/ml (in the typical range of model lactobacilli), and pH-lowering capacities to a pH as low as 4.03 in common plant-based (coconut, soy, and oat) and cow milk beverages when cultured up to 72 h at 37°C. These properties were especially pronounced in coconut beverage and butter milk fermentations, and were sustained in co-culture with the model starter Streptococcus thermophilus. Furthermore, L. reuteri AMBV339 grown in laboratory media or in a coconut beverage survived in gastric juice and in a simulated gastrointestinal dialysis model with colon phase (GIDM-colon system) inoculated with fecal material from a healthy volunteer. Passive transport of L. reuteri AMBV339-produced riboflavin occurred in the small intestinal and colon stage of the GIDM system, and active transport via intestinal epithelial Caco-2 monolayers was also demonstrated. L. reuteri AMBV339 did not cause fecal microbiome perturbations in the GIDM-colon system and inhibited enteric bacterial pathogens in vitro. Taken together, our data suggests that L. reuteri AMBV339 represents a promising candidate to provide riboflavin fortification of plant-based and dairy foods, and has a high application potential in the human gastrointestinal tract.

The presence of Bifidobacterium species in the maternal vaginal and fecal microbiota is arguably an evolutionary trait that allows these organisms to be primary colonizers of the newborn intestinal tract. Their ability to utilize human milk oligosaccharides fosters their establishment as core health-promoting organisms throughout life. A reduction in their abundance in infants has been shown to increase the prevalence of obesity, diabetes, metabolic disorder, and all-cause mortality later in life. Probiotic strains have been developed as supplements for premature babies and to counter some of these ailments as well as to confer a range of health benefits. The ability to modulate the immune response and produce short-chain fatty acids, particularly acetate and butyrate, that strengthen the gut barrier and regulate the gut microbiome, makes Bifidobacterium a core component of a healthy infant through adulthood.